Effect of natural feeding with marine meiobenthic and biofloc organisms on production parameters in Penaeus vannamei shrimp culture

Con el crecimiento demográfico, el consumo de camarón aumenta exponencialmente, por lo cual es imprescindible la búsqueda de nuevas tecnologías que disminuyan costos y optimicen la producción. Los sistemas biofloc compuestos por bacterias, algas, protozoos y metazoos han sido considerados una alternativa eficiente como suplemento alimentario en el cultivo de camarón. Además, el suministro de meiofauna en los cultivos tiene efectos positivos en el crecimiento del camarón debido a su alto contenido proteico y de ácidos grasos poliinsaturados. Se evaluó el efecto de la alimentación natural con organismos del meiobentos marino y biofloc sobre los paramentos de producción en el cultivo de Penaeus vannamei. El ensayo se realizó en temporada de verano y se analizaron parámetros de calidad del agua e indicadores productivos. La densidad inicial de cultivo fue 40 postlarvas por 0,18 m2. Se utilizó un diseño experimental completamente aleatorizado conformado por cuatro tratamientos con tres réplicas. En el tratamiento 1 (B), se utilizó la tecnología convencional para cultivo de camarón, con alimento balanceado y agua de mar.  En el tratamiento 2 (S) se colocó una capa de cinco centímetros de sustrato arenoso fino y alimento balanceado. En el tratamiento 3 (S-Bf) se añadió sustrato, biofloc y alimento balanceado. En el tratamiento 4 (B-Bf) se aplicó biofloc y alimento balanceado. Los valores de temperatura, pH, salinidad, oxígeno disuelto, sólidos suspendidos, nitrito, nitrato y amoniaco se mantuvieron dentro de los parámetros óptimos para la especie. El tratamiento que tuvo el mayor peso final fue S-Bf (1,17 g) y el tratamiento que reportó menor peso fue el B con 0,76 g. Los resultados sugieren que la combinación de los flóculos bacterianos del biofloc más los micro invertebrados meiobentónicos pueden constituir una estrategia para mejorar la productividad del cultivo y mantener los parámetros ambientales en intervalos óptimos.With human population growing, shrimp consumption increases exponentially, which is why the search for new technologies that reduce costs and optimize production is essential. Biofloc systems, composed of bacteria, algae, protozoa, and metazoan, have been considered an efficient alternative as a food supplement in shrimp farming. Furthermore, the supply of meiofauna in crops has positive effects on shrimp growth due to its high protein and polyunsaturated fatty acid content. The effect of natural feeding with marine meiobenthic organisms and biofloc was evaluated on the production parameters in the Penaeus vannamei culture. The test was carried out in the summer season and water quality parameters and productive indicators were analyzed. The initial culture density was 40 postlarvae per 0.18 m2. A completely randomized experimental design was used with four treatments and three replications. In treatment 1 (B), the conventional technology for shrimp culture was used, with dry feed and seawater. In treatment 2 (S) a layer of five centimeters of fine sandy substrate and dry feed were used. In treatment 3 (S-Bf) substrate, biofloc, and dry feed were used. In treatment 4 (B-Bf) biofloc and dry feed were applied. The values ​​of temperature, pH, salinity, dissolved oxygen, suspended solids, nitrite, nitrate, and ammonia were kept within the optimal parameters for the species. The treatment with the highest final weight was S-Bf (1.17 g) and the one with the lowest weight was B with 0.76 g). The results suggest that the combination of bacterial flocs of the biofloc plus the meiobenthic microinvertebrates can become a strategy to improve the productivity of the culture and maintain the environmental parameters in optimal intervals. &nbsp

Cytogenetic and genomic analysis of a patient with turner syndrome and t(2;12): a case report

Background: Turner syndrome is a genetic disorder that afects women. It is caused by an absent or incomplete X chromosome, which can be presented in mosaicism or not. There are 12 cases of Turner syndrome patients who present structural alterations in autosomal chromosomes. Case presentation: The present case report describes a patient with a reciprocal, maternally inherited translocation between chromosomes 2 and 12 with a mosaicism of X monosomy 45,X,t(2;12)(p13;q24)[95]/46,XX,t(2;12)(p13;q24) [5]. Through genetic mapping arrays, altered genes in the patient were determined within the 23 chromosome pairs. These genes were associated with the patient’s clinical features using a bioinformatics tool Conclusion: To our knowledge, this is the frst case in which a translocation (2;12) is reported in a patient with Turner syndrome and confrmed by conventional cytogenetics, FISH and molecular genetics. Clinical features of our patient are closely related with the loss of one X chromosome, however mild intellectual disability can be likely explained by autosomal genes. The presence of familial translocations was a common fnding, thus emphasizing the need for familiar testing for further genetic counselling